Epidemiology and laboratory diagnosis of hantavirus (HTV) infections

Quick electrochemical immunoassay for hantavirus detection based on biochar platform

This work describes the first method using biochar (BC) as carbonaceous platform for immunoassay application. BC is a highly functionalized material obtained through biomass pyrolysis under controlled conditions. Due to the highly functionalized surface, covalent binding between BC and biomolecules can be performed by EDC/NHS conjugation. The application of the modified electrode was done with Hantavirus, that are etiologic agents mainly transmitted by wild rodents. Among its pathologies Hantavirus Cardiopulmonary Syndrome (HCPS) arises at Americas, caused by Hantavirus Araucária and reaches 40% lethality. The diagnostic is based on the presence of specific hantavirus nucleoprotein (Np), under viremic condition or IgG2b antibodies (Ab), during first symptoms. The results presented a device sensitivity of 5.28 μA dec^-1 and a LOD of 0.14 ng mL^-1 to the Np detection, ranging from 5.0 ng mL^-1 to 1.0 μg mL^-1, the Ab detection works as qualitative type sensor above 200 ng mL^-1. Both sensors were evaluated its selectivity and serum samples; selectivity against Gumboro disease, VP2 protein, and antibody IgG2a against Yellow fever disease (YF), respectively. So, the devices here proposed are promising tool suitable for both rodent and human hantavirus clinical surveys.

'Bedside assessment' of acute hantavirus infections and their possible classification into the spectrum of haemophagocytic syndromes

Hantavirus infections, recently renamed 'hantavirus fever' (HTVF), belong to the most common but also most underestimated zoonoses in the world. A small number of reports described the so-called 'lipid paradox' in HTVF, i.e. the striking contrast between a very low serum total cholesterol and/or high-density lipoprotein cholesterol (HDLc), and a paradoxical concomitant hypertriglyceridaemia. In a prospective study, with patients being their own control after illness, we wanted to verify if this quick and easy 'bedside test' was robust enough to warrant a preliminary diagnosis of acute kidney injury (AKI) caused by HTVF. The study cohort consisted of 58 Belgian cases (mean age 44 years), admitted with varying degrees of AKI and of thrombocytopaenia, both characteristic for presumptive HTVF. All cases were sero-confirmed as having acute HTVF. At or shortly after hospital admission, a significant (p < 0.001) decrease of total cholesterol and HDLc was found in comparison with normalised levels in the same cohort, quantified a few days after spontaneous AKI recovery. Conversely, fasting triglyceride levels during HTVF infection were significantly (p < 0.001) higher during illness than after recovery. This 'lipid paradox' was most outspoken in severe HTVF cases, often accompanying, or even predicting, major kidney or lung complications. Thus, this 'bedside assessment' seems to hold even promise for presumptive diagnosis of more severe so-called 'hantavirus cardio-pulmonary syndrome' (HCPS) cases, mostly described hitherto in the New World. In more severe AKI cases, the mean total cholesterol was significantly lower (p = 0.02) than in milder cases, i.e. cases with peak serum creatinine levels of < 1.5 mg/dL. Thrombocytopaenia, generally accepted as the severity index in HTVF, appeared, moreover, significantly correlated with serum levels of total cholesterol (R = 0.52, p < 0.001) and with serum levels of HDLc (R = 0.45, p < 0.01). A link with the novel clinical entity of haemophagocytic syndromes, also characterised by manifest hypertriglyceridaemia, is discussed.

Hantavirus: an infectious cause of acute kidney injury in the UK

We present a case of an undifferentiated febrile illness in a 59-year-old man from East Yorkshire. He was initially treated for leptospirosis due to the fact that he had farm exposure and the findings of acute kidney injury (AKI), thrombocytopenia and a raised alanine transferase (ALT) on his initial blood results. Serology tests later proved him to have had another rodent-borne illness: hantavirus. An investigation by Public Health England (formerly known as Health Protection Agency) (PHE) went on to prove the presence of the same serotype of hantavirus in rats caught on the patient's property. After an initial deterioration, the patient made a relatively uneventful recovery and all his blood tests returned to normal levels.

Bartonella henselae infection inducing hemophagocytic lymphohistiocytosis in a kidney transplant recipient

Bartonella henselae (Bh) is the cause of cat-scratch fever. When infection is symptomatic, it typically presents with singular lymphadenitis and fever. Less commonly, the infection can become disseminated and cause endocarditis, osteomyelitis, and micro-abscesses in multiple sites including liver, spleen, eyes, and brain, especially in immunocompromised patients. Hemophagocytic lymphohistiocytosis (Hlh) is a rare and severe multisystem disorder that may be triggered by infections. In one prior case, Bh, like other infections, has induced Hlh, an immune-mediated disease that can be characterized by septic-like presentation with persistent fevers, hepatosplenomegaly, and pancytopenia. In an immunocompromised transplant recipient, the onset of Hlh can be difficult to discern from a severe presentation of Bh. We report a case of criteria-proven secondary Hlh occurring after Bh infection in an 11-yr-old girl who was 13 months post-renal transplant. The patient developed multi-organ failure, and her severe clinical presentation required a thorough evaluation for infectious and non-infectious possibilities including post-transplant lymphoproliferative disorder and rejection. Early recognition of Hlh allowed for better directed therapies, leading to recovery of the patient and resolution of both Bh and Hlh.

Serological evidence of hantavirus infection in farm and abattoir workers in Trinidad--a preliminary study

Hantaviruses are established causative agents of hemorrhagic fevers and renal diseases amongst other clinical manifestations in humans, with most diagnosis based on serological assays. The disease, which is rodent-borne, has been reported in numerous countries worldwide but information about the disease is scanty in the Caribbean. The objective of this investigation is to determine the frequency of exposure to hantaviruses in a selected apparently healthy human population associated with abattoirs and livestock farms in Trinidad using a hantavirus immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). Of a total of 236 individuals tested, 27 (11.4%) were seropositive for hantavirus infection. Amongst abattoir workers the frequency of infection was 9.4% (6 of 64) compared with seropositivity rate of 12.4% (18 of 145) and 11.1% (3 of 27) amongst livestock farm workers and office workers and other individuals with minimal animal contact respectively. The differences were, however, not statistically significant (p > .05; χ(2) test). Age, gender, and race did not significantly affect the infection rate by hantavirus in the workers studied. This is considered the first documented evidence of hantavirus infection in Trinidad and Tobago. It is imperative for local physicians to consider hantavirus as a differential diagnosis in patients with hemorrhagic fever and renal diseases, since there may be a number of undiagnosed cases of hantavirus disease in the human population in the country.

Hantaviruses: Immunology, Treatment, and Prevention

Hantaviruses are rodent-borne bunyaviruses that are associated with two main clinical diseases in humans: hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. It has been suggested that host-related immune mechanisms rather than direct viral cytopathology may be responsible for the principal abnormality (vascular dysfunction) in these syndromes. This review summarizes the current knowledge on hantaviral host immune responses, immune abnormalities, laboratory diagnosis, and antiviral therapy as well as the current approaches in vaccine development.

Plasma Exchange--Associated Immunoglobulin M--Negative Hantavirus Disease after a Camping Holiday in Southern France

A 37-year-old Belgian patient presented with acute nephropathia epidemica (NE) shortly after a camping holiday in southern France. Unusual symptoms were initial noncardiogenic lung involvement, followed by severe acute renal failure, acute acalculous cholecystitis, presence of immunoblasts in the bone marrow, and hemolytic anemia, presenting as hemolytic uremic syndrome. Positive immunoglobulin (Ig) A and rising IgG titers against Puumala hantavirus (PUUV) were detected, but IgM remained negative on days 8 and 20. The results of reverse-transcriptase-polymerase chain reaction performed on day 8 were positive for PUUV. This is the first report of an iatrogenically IgM-negative hantavirus case due to the selective removal of heavy-weight molecules during plasma exchange via the centrifugation technique. This is also the first report of proven NE from the Mediterranean part of France.

Hantavirus

When hantaviruses hit the headlines with the advent in May 1993 of a new disease in the USA, and later in the New World from Canada to south Argentina, called "hantavirus pulmonary syndrome" (HPS), speculations in the lay press rose from the very beginning around the possibilities of a biological warfare (BW) weapon. Indeed, the responsible agent of HPS, hantavirus, was almost unknown at that moment in the New World, was airborne, seemed to target preferentially young adults, and induced a devastating cardio-pulmonary collapse with a high case-fatality rate (50%), often within hours. It quickly became clear, however, that the same scourge had been known for many years in the Old World under different and mostly milder presentations. With the rapidly increasing knowledge about hantaviruses, it also became clear that they lack many of the potentials of an "ideal" BW weapon, as will be explained in this paper.